The present invention in one of its forms relates to a dry-process apparatus for producing archival microform records of computer stored data or other electrical signal data sources. The apparatus in some respects is similar to that disclosed in U.S. Pat. Nos. 3,966,317 and 4,123,157, but is different therefrom in its most preferred form in that it produces microform records from hard copy-appearing images on a cathode ray tube screen rather than from hard copy directly, and at a much higher speed of operation made possible by the use of a tapered fiber optic filament bundle and by the manner in which the masking film strip is supported and advanced past the various stations of the apparatus. The apparatus disclosed in these patents includes an imaging station wherein a light image reflected from the hard copy is reduced through a mirror and lens system to micro-image size and applied to a heat developable dry-process masking film strip, like one made of a dry silver film, which is photosensitive to and imaged by the light reflected from the hard copy and which is developed by heat to provide micro-imaged transparencies therein where the light preferably forms a dark opaque background for transparent data-forming portions of the image produced therein. The heat application times necessary to develop such films generally take a number of seconds. The apparatus also includes an image transfer station where the micro-image records of the transparencies produced in the masking film strip are transferred by radiant energy above a certain critical value passing therethrough to an initially opaque archival dry-process microfiche card-forming film which is not very sensitive to hard copy reflected light, but is sensitive to and made transparent without any developing in those regions thereof struck by the radiant energy above the certain critical value. The final image thus produced is a negative of the original hard copy image and has archival properties. Since only the originally dark data-indicating portion of the original hard copy image affects the microfiche card-forming film, the film has add-on capabilities. The apparatus disclosed in said U.S. Pat. No. 4,123,157 includes features for enabling a previously partially imaged frame of the microfiche card-forming film to be moved into a projection position where the frame image is projected onto the platform so that an overlay piece of hard copy can be placed on the platform and positioned thereon to transfer data thereon to still unimaged portions of the microfiche frame involved.
It was not initially appreciated that the apparatus as disclosed in the aforesaid patents could be effectively used in recording information fed directly from cathode ray tube images. In the past, microform records have sometimes been made from computer data by using a computer data controlled laser beam scanning small areas of a recording film to provide micro-sized characters representing alpha-numeric and other data. However, laser beam scanning equipment designed for this purpose is relatively expensive, and because of OSHA restrictions are not presently useable in business offices and the like. Also, cathode ray tube images where the alpha-numeric data is directly formed by the lighted portions of the cathode ray tube screen have been reduced in size and applied to a film to form microform images thereon. The microform film used did not have add-on capabilities, and there was probably no particular thought given to the advantages of providing alpha-numeric data formed by back-lighted portions of the cathode ray tube screen which form dark alpha-numeric characters or other data.